1. Field of the Invention
The present invention relates to an image forming device such as an MFP (Multi-Functional Peripheral), as well as a technique relating to such an image forming device.
2. Description of the Background Art
Conventionally, there is a technique for viewing, changing, and the like of information relating to an image forming device, such as an MFP, having a web server built therein, by accessing the web server from a web browser in a device external to the image forming device.
Due to reasons such as limitation of a memory capacity (RAM capacity or the like), such an image forming device has an upper limit for a number of communication sessions by the web server in the image forming device (in other words, a number of external devices (or the web browsers) with which the web server is able to establish a communication session).
By contrast, there is a technique for effectively utilizing such a limited number of communication sessions (see Japanese Patent Application Laid-Open No. 2003-233585, for example). According to Japanese Patent Application Laid-Open No. 2003-233585, after one communication session is established, a request is transmitted from a client to a server periodically (at regular intervals) to confirm whether or not to continue the communication session. According to this technique, the communication session continues if a request is transmitted from the client to the server within a certain period (e.g., one to several minutes), and the communication session is terminated if a request has not been transmitted over a period longer than the certain period.
In the meantime, examples of the external device (external terminal) accessing the web server in the image forming device include devices such as so-called tablet terminals, in addition to personal computers. For tablet terminals (in particular, OSs (operating systems) for tablet terminals), various measures have been made in order to use limited hardware resource effectively. For example, regarding an operation of the web browser, a script embedded in a web page is activated during a period in which the web page is active (active period), but the script is not activated during a period in which the web page is not active (non-active period).
Therefore, according to the above technique (Japanese Patent Application Laid-Open No. 2003-233585), in a case in which a periodic request is transmitted from a web browser to a web server using a script embedded in a web page, if the web page becomes non-active, the script in the web page is not activated, and a periodic request is not transmitted. Then, the web server determines that the web browser is no longer used (continuation of the communication session is unnecessary), and disconnects the communication session with the web browser (client). As a result, a user operating the web browser is forced to perform a connection operation or the like to re-establish a communication session with the server.
As described above, there is a problem due to the fact that, in a case of accessing a web server from a browser that operates in a tablet terminal or the like, a request script in a parent page is not activated when a child page is called from a parent page displayed in the browser and the parent page is made non-active and the child page is made active.
The above problem may similarly occur not only in the case in which a parent page includes a script for transmitting a periodic request for maintaining a communication session as described above, but also in which the parent page includes a script for periodically displaying device information of an image forming device. For example, there may arise a problem that the device information in the parent page is not updated while the child page is being displayed, as a script in the parent page for updating the device information is not activated when the child page is called from the parent page displayed in the web browser and the parent page is made non-active and the child page is made active.